1. Field of the Invention
The present invention pertains to water purification systems and more particularly pertains to such systems adapted for domestic use.
2. Description of the Related Art
Previous systems have been proposed in the past for providing purified water to a domestic user. One use for such purification systems is to provide a supply of purified drinking water. Some early domestic systems had a filtration apparatus disposed on the countertop, adjacent a sink. A connection was made to the sink faucet to obtain a supply of water to be purified and an outlet from the apparatus was placed in the sink to discharge the brine or concentrate and impurities. Examples of this type of water filtration are given in U.S. Pat. Nos. 3,746,174, 3,822,018, 4,609,463 and 4,713,175. Apparatus of this type blocked access to the sink area and also interfered with the use of the sink faucet.
In a second type of system these problems were overcome by mounting the filtration apparatus under the counter where the sink is located. Examples of water filtration systems directly connected to plumbing and piping systems are given in U.S. Pat. Nos. 4,218,317 and 4,540,489. A third example of water purification systems of this type is given in U.S. Pat. No. 4,711,723 which has a base which can stand upon a horizontal support surface but the water purification apparatus nonetheless requires piping connections to a source of tap water and to a drain for impure water discharge. These systems all require substantial plumbing changes to install connections to the water piping and the drain for the sink. More recently, filtration apparatus has been provided which mounts directly onto the sink faucet. However, access to the sink faucet is obstructed when the filtration apparatus is installed. Accordingly, there is still room for improvement to water filtration units, especially filtration units for domestic use at a kitchen sink or the like.